Actually lighting the fuel/oxidizer mixture in a rocket engine is a small but critical part of rocket science, and there are a number of techniques exploited to make sure that mission control gets to call out ignition.
Not bored, just quickly bored of being a “Hey Guys, What’s up?” American. (Nothing’s Up, why are you asking?). And he speaks the “pearfekt” English (roll that R in pearfekt) that only the Scots can achieve. No one needs subtitles, no Yankee garbling, And now, at last, I know that the spray of sparks under the main nozzle is not the master match.
As an Apollo Era Aerospace Engineer, I started this video with a touch of skepticism, but was greatly impressed in the end. Thanks much for the very informative and well done narrative. As an aside, some early pyro igniters for liquid bi-prop engines were actually quenched by the LOX inflow, hard to believe. Plasma and Pyro Igniters were also tried for the LR-10 wth success. Laser ignition was used at Thiokol in 1963 for solid motors!
oak one of my friends said the Russians used burning wooden board shoved up into the combustion chamber to light off the Soyuz he was filming! Crazy Russians.
i thought the water spray is for cooling purposes while it is instead mainly for noise reduction. The soundwaves at a start are such violent, they would severely damage the launchpad if they weren't dampened
+Hirschi74 not just the launch pad! The sound waves reflect off the launch pad (tearing bits of concrete loose in the process!) and hit the vehicle, which can cause pressure fluctuations in the combustion chambers of rocket engines directly above it (and this can be a self reinforced process, making it worse until they destroy themselves) , and can even collapse fuel tanks in extreme cases. It's a seriously bad thing.
It was widely thought the sparks on the Space Shuttle pad were for engine ignition because this disinformation was repeatedly broadcast as the explanation for why the shuttle engines couldn't restart.
As I am watching, I am thinking, "what are those sparks that shoot out from the...uh...oh...well, thanks for answering my mental question at exactly the right time."
Those are to ignite and burn off any stray Hydrogen so there isn't an explosion in the blast trench when the engines ignite, they don't have anything to do with igniting the engine itself.
General Incompetence even though you turned off revert flight in career mode to make it more difficult, you ignore that and turn on allow reverting flights.
I absolutely love these informative videos of yours. They fill the hole that early 2000s Discovery Channel documentaries used to. Keep up the good work. And as usual, Record Safe.
What do you mean? Duck dynasty is totally educational hahaha. I loved the tales of the gun series and stuff like the battleships series. Thankfully its on RU-vid.
Wow, you clearly explained what has to be a very technical subject. Now I'm going to be watching for green flashes with all the SpaceX launches. BTW, I'm 61 and watched most of the Gemini, Saturn and later most Shuttle launches starting in the 60s and into the future. Sat on the floor in the living room and watched man walk on the moon. Watching Falcon 9 boosters land is now the biggest thrill I get these days.
pschroeter1, this is very interesting and really great stuff alright and I hate to stray off-topic but something has been bugging me for years that maybe you can answer. When I was a little kid I was watching a Saturn V launch on TV that was stopped at 17 seconds before lift off and the launch was aborted but I can't remember what Apollo mission that was. I think it was Apollo 16 but I'm not sure. The count down went to T - 17 seconds and then a hold was put in and the mission was postponed.
I didn't know, but was curious enough to try and find out. Wikipedia says: "The launch of Apollo 16 was delayed one month from March 17 to April 16. This was the first launch delay in the Apollo program due to a technical problem." I Googled Apollo moon launch abort and didn't see any aborts during launching. Apollo 12 was hit by lighting at launch which caused some scary looking problems without aborting the mission.
Thanks for the reply. That must have been it; Apollo 16. I sure became hooked on the Apollo space program ever since. I have seen the Saturn V in Florida and in Houston. Thanks again for the mutual interest.
7:35-7:46 Thank you for clearing that up for me Scott. When I was a kid, I thought that's how they ignited the engine, "Oh they must force flammable gas and the Sparks ignite said gas on liftoff". As I got older I realized that wasn't the case. But I was still curious as to why they did that. You learn something new everyday, like how a few weeks ago I learned those engines on the Space Shuttle were only used for liftoff and moving in space was done via RCS. Which are the two on the side of the three engines. Again, as a kid I thought those were backups in case one of the three main engines failed.
@@wingracer1614 Do you have any sources about that? Why someone would use a detonation to initiate a deflagration on such safety critical component. Considering usually solid rocket fuels contain large amounts of ammonium perchlorate which can detonate. I would guess is actually some short of thermite instead of a detonator.
@@metanumia Sure it would work but it needs to be for initiating some short of pyrotechnic mixture that deflagrates and ignites all the fuel, not a detonation train as happens in a detonator. If you use the exploding bridge-wire, arc generator or spark gap to directly ignite the fuel you run in to the problem that you need a huge power supply to do so which isn't very practical in the case of a rocket. Something somewhat related and that uses your idea of an arc generator are ETC guns (Electro Thermal ignition Chemical guns) which is basically a conventional powder gun with a special plasma torch instead of a primer on the cartridge, this device generates a huge plasma plume inside the casing, this makes the powder burn much more uniform and in a controlled manner as you can control its burning by modulating the current going into the plasma cartridge also you can use special propellants with higher speed of sound/energy but that are harder to ignite and control. This is being researched a lot since the early 90's to increase the muzzle speed of tank rounds while also reducing erosion and high pressures because conventional tank guns are already at the limit of what is possible with normal technologies (muzzle speeds of around 1800m/s) its crazy.
6:00-6:05 Scott says: tri-ethyl borane YT subtitles: trifle boring Yeah, like anything having to do with large rockets is either a "trifle" or is "boring." Good job speech-to-text. ;-D
I don't think it would actually be great. At first it might be interesting, but later is just something annoying that you have to micromanage every single time.
Anyone interested in some of the hair-raising history of rocket fuels and oxidizers should really read through "Ignition! An Informal History of Liquid Rocket Propellants". It contains some real howlers: "If Tannenbaum's mixtures were bad, that proposed at a monopropellant conference in October 1957 by an optimist from Air Products, Inc., was enough to raise the hair on the head of anybody in the propellant business. He suggested that a mixture of liquid oxygen and liquid methane would be an extra high-energy monopropellant, and had even worked out the phase diagrams of the system.* How he avoided suicide (the first rule in handling liquid oxygen is that you never, never let it come in contact with a potential fuel) is an interesting question, particularly as JPL later demonstrated that you could make the mixture detonate merely by shining a bright light on it."
They just re-published Ignition! and I really recommend it if you're any kind of a rocket nerd. It's fun and informative, and makes me really glad I didn't faff around with liquid fuels when I was wanting to build a rocket myself.
Fascinating. At least some afterburners other than the SR71's (for example the J79) were also using a torch igniter similar to the SSME's.I don't know about later designs. Anyway, thanks a lot; I had really no clue about rocket engine ignition. The more I learn, the more I realise all the things I don't know :)
This is, without question, the best series your channel has ever had. Please don't stop! :) However, I did notice the description is lacking "learn more" links. I know everyone knows how to Google, but honestly, I believe people are too lazy for that. Links in the description might earn some clicks though :P
Why Cs?, it would needed to be warmed up since it's nearly solid at room temp. I would probably try NaK, since it's liquid at wide range of temps and highly reactive. It will ignite in the presence of oxygen. Hey Cody, maybe you should try an experiment to see how it burns in oxygen compared to how burns in open air, no water present. I would try it myself, but I can't find any NaK around.
Damn Scott, I just love your videos and your explanations. You made KSP enjoyable for me, took away my dependence on Mechjeb, and despite being a life long space enthusiast, I've never given much thought to just how complex something like igniting or re-igniting a rocket would be. Thanks :)
Love your Videos Scott! Especially those scientific ones. You've got such a good way of explaining things in an easily understandable manner! Which is something only the best minds can do, in my opinion. I'm an aerospace student myself and while we've got pretty good profs I appreciate and enjoy your videos a lot. That's how teaching has got to be done! Kind regards from Germany! :)
Scott, thank you. I could not find information on this anywhere online. Thank you so much. Tell me, where did you learn so much about rockets and space exploration technology?
Ever since your last video (the one on engine nozzles) I've been noticing the engine bell sizes on literally every engine that I've seen. And now I will look for the green flashes in SpaceX videos. Please continue this series, I really enjoy it
I once heard a story of mechanics starting the jet enginges of the MiG 21 by throwing a burning piece of fabric in it when the automatic ignition failed so giant matches start to look pretty harmless
XCOR Aerospace USE to have videos on it's website of their electrical igniters for rocket engines. They honest to god looked like they had an off the shelf car spark plug sticking out of the side of them and would shoot out a little ~4" jet of blue flame with teeny shock diamonds and everything.
Followed your recommendation and started reading the book 'Ignition!', what a great read. I love his dry humour and honesty. What an amazing field to be involved in at the time.
KSP pumps are the best pumps, don't understand why they bother with the whole rocket engine makarky, just eject fuel at a fraction of the speed of light.
but that adds a little in work and the fuel it goes unburnt, and this beat the purpose of the fuel. And last, injecting something into fraction of c requires a lot of energy
7:30 Explained one of the ignition questions I had. When I saw the sparks I thought they were used to ignite the Oxygen and Hydrogen fuels. Thanks for the answer.
Gimballed engines have the capacity to move their exhaust nozzles which obviously alters how thrust from that engine affects the craft. A couple examples on planes here, gfycat.com/BelovedScaredCoot and here, gfycat.com/DishonestCooperativeAmericanratsnake
The first stage of this rockets don`t need to be restarted, that is why they don't implement ignition system in engines themselves. It makes the engine simplier and a bit lighter.
You light a rocket with a punk. Sadly, with the world's reserve of Ramones at an all-time low, it's getting harder to find qualified punks to light rockets to the tune of "Holiday in Cambodia".
Dear Scott, is it possible to know your opinion about Russian engines used to lunch New Horizons, Lunar Reconnaissance Orbiter, Mars Reconnaissance Orbiter and many others? I'm asking because i think it is not the first time I hear a bit of sarcasm in your voice concerning the engineers and scientists who first in theory and then in practice opened the cosmic era for the humanity. Best regards. =)
As I mentioned it's more to do with being aerospace engineers who generally don't like changing anything that works just fine. Trust me I have masses of respect for everyone involved. It's not sarcasm at all. Also worth checking out my comment about the Russian built engines used on the spectacular Antares launch failure ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-P5shc52QLQ0.html
Wow, well Kerbals are really lucky they don't have to climb up into engines to place ignition devices......enough of those poor bastards die as as it is, let alone having some giggly player activate the engines while they're placing one inside a glorified blast furnace.
Tregeta But That seems like such a perfectly Kerbal arrangement. In my head the Minions of Despicable Me are clearly visitors from Kerbin. Probably slightly mutated by the hazardous dirty nuke rockets their starships used, of course.
We think technology has advanced so far to get us into space (and it has), but all of our advancements still have vestiges of archaic solutions as illustrated by the "space-age match". Another example is nuclear power plants; the iconic symbols of humanity breaking into the nuclear age (aside from the mushroom clouds I suppose) are still just steam-engines at their base.
In some ways, for a steam turbine, it's more that we've yet to make something better; funny when you consider how old the earliest examples of a steam turbine are. Whether you take that to mean we suck or that the original engineers of the steam turbine were geniuses is up to you of course. Not that there aren't alternatives of course (a Sterling engine for example) but (to my limited knowledge) thermal energy isn't something that's easy to convert into other forms, or certainly not kinetic/electrical. Plus, as they say: "if it ain't broke, don't fix it."
Everything has a learning curve. Ours are exacerbated by corporate economics and military needs (and their economics), but they will eventually come around. At this point in time, we've pretty much perfected steam boilers, so that's what is used, as opposed to perhaps MHD systems.
What is exacerbated is the lack of efficiency of movement from the basic to the sophisticated in the design. For example, there is much foot-dragging by the existing nuclear industry towards better designs for fear that the standard ceramic-uranium-zirconium clad fuel bundle - milch cow will be made obsolete, and so we continue spending huge amounts on obsolete technology.
puncheex2 Is that why the nuclear industry is dragging? I thought it was more that the public is scared shitless of invisible phantoms and don't want nuclear reactors built.
I love these videos, super interesting for us armchair rocket scientists!! Keep em coming! (I would love to hear more about what you were talking about right before the video ended, I am very curious about the innards of the rocket fuel chambers (also the engines themselves, but many people cover rocket engines, I would like to know more about how the fuel tanks work!))
Hey Scott. I'd be super interested to hear more about those safety systems you mentioned near the end. That could be an interesting topic for a new video.
Damn, I actiually learned something today! :D I thought those sparks under the Space Shuttle were involved with the lighting, but now I know they don’t. Good work! :)
We use a big squirt of TEAL/TEB 85/15 on our hotfires for ignition. It's common in most NewSpace companies because it's a COTS hypergolic available from one specific US chemical supplier, removing the complication of needing to manufacture it on-site. The green startup flames from the presence of boron is very short-lived and you're unlikely to see it in real-time footage, but it's very prevalent in high-speed footage.
Scotty, loved this. I said yep a lot. You are an amazing educator duder. When I tell people about launching ICBM's they cant understand that a tertiary rocket motor gets her engaged. I am submarine warfare qualified and I don't know if it was hyperbolic or not. Please do a video on Trident Missiles!!!!
Thank You VERY MUCH for the informative video. I have always wondered about the "sparklers" they lit off prior to engine ignition but not really found the actual answer. And, every time I've ever been to KSC and met Astronauts there, I've always had other questions and forget to ask that one until I watch the next launch and kick myself for never having asked.
Scott Manley: don't think it as simple as scientists using big matches to light up rockets. Also Scott Manley: think of this system as large high tech matches to light up the rocket
